Out of the box, the external monitor key (Fn-F7) on my Lenovo X300 didn’t work. I found a great post on the ThinkWiki that described how to do it. I followed the instructions up to and including the “set permissions and restart acpi” section.

There was one small problem with the bash script that you put in /usr/local/sbin/thinkpad-fn-f7. Lines 39 and 40 didn’t get the right values when one of the monitors was off, but still connected. I changed them to:

INTERNAL\_STATE=$($SU xrandr | sed -n "s/$\{INTERNAL\_OUTPUT}\\Wconnected\\W(\[0-9\]+\[xX\]\[0-9\]++\[0-9\]++\[0-9\]+).\*/\\1/p")  
EXTERNAL\_STATE=$($SU xrandr | sed -n "s/$\{EXTERNAL\_OUTPUT}\\Wconnected\\W(\[0-9\]+\[xX\]\[0-9\]++\[0-9\]++\[0-9\]+).\*/\\1/p")

and all was good.

I posted my experience to the ThinkWiki discussion on the topic, so hopefully by the time you read this the fix will have been made there.